Amplifier Version 1.0

By
Chad Rempp
2007/12/29

This was a simple experiment to built a 1 watt amplifier and speakers in
order to gain some experience to ultimately build my
amplifier version 2.0
(which, due to cost will take a while to finish). I mostly used parts
I had on hand.

Speakers

FIG 1. Assembled Speakers

The speakers are cheap 8 Ohm speakers that are found everywhere. These
came from old computer cases. For the enclosure I used cardboard boxes
that held passives I ordered from Jameco. I cut a circular hole in the
bottom of the box and hotglued the speaker to the box. The flap is on
the back and allows access to the inside. These sound like crap but the
enclosure does provide some resonence that makes it louder.

Amplifier

FIG 2. Assembled Amplifier

FIG 3. Amplifier Circuit

This is a simple 1 watt (my calculation) amp that uses the LM386. For
stereo you simply duplicate the circuit for each channel. After alot of
work I fit two channels in the case but but but realized too late that
by mirroring the layout the pins on the LM386 change. I tried to hack
it to work but ended up pulling everything for the second channel so
now it's only mono.